Many coffee shops serve an array of coffee products, from mild to strong coffees brewed from coffee beans grown in different areas of the world, each imparting a particular flavour and aroma. Due to the limited counter space available to coffee shops, only a small selection of coffees are served each day, as coffee pots, heat plates and coffee bean grinders occupy a significant portion of the counter space. This selection can include strong, mild or medium roast coffees brewed from a variety of coffee beans.
In addition to these “standard” coffees, a selection of flavoured coffees are also served. Examples of such flavours include amaretto almond, French Vanilla and Irish cream. One method of providing flavoured coffees is to obtain flavoured coffee beans with the flavouring infused into the beans, and grinding them for brewing a pot of the flavoured coffee. Another method is to use pre-packaged, ground flavoured coffee. A third method is to is to stock a selection of flavour syrups that can be directly added to any regular cup of coffee by the server. This technique provides more flexibility since the flavour can be added to any standard coffee.
However, because separate grinders are required for grinding standard coffee beans and flavoured coffee beans to ensure that the standard coffee bean grinders are free from contamination from flavoured grounds, valuable counter space is taken up and additional cost is incurred by the extra grinder. Furthermore, flavoured coffees tend to stew in their pots for a relatively long period of time since they may not be as popular as the non-flavoured coffees. Those of skill in the art are well aware that coffee left standing on a heat plate for too long is unpalatable due to poor taste. Therefore, additional cost is incurred as unsold flavoured coffee must be thrown out in favour of freshly brewed flavoured coffee. Although use of pre-packaged flavoured coffee obviates the need for an additional grinder, the problem with limited counter space and aged coffee persists. Furthermore, the consumer perception that pre-packaged coffee cannot be as fresh as freshly ground coffee tends to curb consumers from purchasing pre-packaged, flavoured coffee.
Bottles of flavoured liquids, or syrups, are easily stored upon shelves and countertops, and a wide selection of flavours can be made available to the consumer. Unfortunately, consistency of flavour between different servings is difficult to achieve because the dose of syrup added to each cup of coffee is subject to human error. Furthermore, the optimal dose of syrup changes for different sized cups of coffee, and for different types of beverages (cappuccino, lattes, tea etc) to ensure that the flavouring is not over-powering or insufficient for the base beverage. Consistent dosing is further complicated when several flavours are added to the same beverage, as different flavours can overpower others. For example, a mint flavouring can easily overpower a vanilla flavouring of the same quantity. Hence, consistent and accurate dosing of flavourings cannot be achieved when a server is responsible for manually preparing a flavoured beverage.
Another factor for consideration is the concentrated flavouring itself. Manufacturers and retailers prefer to use concentrated flavouring with minimal carrier, as the carrier can affect the flavouring and taste of the flavoured beverage, and the additional volume contributed by the carrier increases shipping costs of the flavouring. Thus, the highly concentrated flavouring to be added can be in the order of several millilitres, depending on the type and size of beverage. Due to the highly concentrated nature of the concentrated flavouring, accuracy of the dispense becomes critical since the absence or addition of one or two millilitres can significantly affect the taste of the beverage.
Known dispensing machines include simple gravity fed valves, peristaltic pumps, pressurized systems and displacement pumps, for dispensing fluids. However, none of these types of machines are suitable for dispensing the very small volumes of concentrated flavouring fluid desired by the industry.
Gravity fed valve dispensing machines simply open and close a valve connected to a tank that releases fluid under gravity in response to a user actuating a lever or switch. Such dispensers are obviously not suitable for accurate and consistent delivery of small amounts of concentrated flavouring fluids since the amount to be dispensed relies upon user control.
Constant mechanical deformation of the flexible tube of peristaltic pump systems changes its elasticity characteristics, and hence the dose it provides over time. Furthermore, known peristaltic pump systems are not capable of dispensing very small quantities of concentrated flavouring fluids.
Current pressure based dispensing systems rely on flow meters which are not sensitive enough to the very small flows required for dispensing the small volumes of concentrated flavourings. Hence their dispensing accuracy is poor, especially since the canister pressure changes as it empties, which introduces a variation in proportions and amounts of fluid dispensed. Furthermore, these systems tend to be difficult to clean and flavours are difficult to change.
Current displacement pumps are designed for dispensing relatively large volumes of fluid, and therefore lack the precision necessary for dispensing small volumes of concentrated flavourings. Current displacement pumps are thus even less suited to dispensing small volumes of high viscosity fluids.
Furthermore, flavourings are not limited to the concentrated flavouring fluids mentioned above. Other products such as chocolate syrups, can be dispensed to create other popular beverages. The problem posed by such additives is their high viscosity rating relative to standard concentrated flavouring fluids. In particular, typical concentrated flavouring fluids have a viscosity rating of two to four centepoise, while certain syrups have centepoise values of about 4000. It is noted that 4000 centepoise fluids are thick and do not flow quickly under gravity. Thus, these products are difficult to dispense through gravity or pressure based dispensing systems. While peristaltic pump systems can be modified to accommodate 4000 centepoise fluids, the high cost renders this approach unfeasible and impractical. Examples of such impracticalities includes the requirement to change fine size to accommodate the different viscosities, and the pump bodies being configurable to accept either two small cartridges or one large cartridge. Since current displacement pumps are designed for dispensing large volumes of low centepoise fluids, they cannot dispense 4000 centepoise fluids accurately.
Hence, to minimize counter space while providing an ample selection of product to dispense, retailers require an apparatus capable of dispensing numerous types of flavourings. However, there are no known dispensers capable of dispensing concentrated flavouring fluids having a wide range of centepoise values, and in volumes of a few millilitres consistently and accurately.
It is, therefore, desirable to provide a dispensing machine for providing any number of concentrated flavourings having a wide range of centepoise values, and in small volumes with high accuracy, for various beverage bases and size combinations.